Substitution bias tends to overstate inflation, because they only reweight once a year (which is much more frequently than what they used to do). And the reweighting of the components won't change the fact that the individual components continue to be published.

Beef is getting much more expensive than it used to be. In the 90's, ground beef used to be cheaper per pound than chicken breast. In the 30 years since, beef has gotten expensive much faster than chicken, and now ground beef costs almost 50% more than ground beef:

Ground beef

Chicken breast